在VSTO C#中获取RTF邮件的附件源内容（HTML格式）

Hey there, I’ve run into this exact headache before—RTF emails are way trickier than HTML ones because their attachment embedding doesn’t follow the clean MIME structure we’re used to. Let’s break down reliable, actionable ways to pull out those attachment source files just like you would with HTML emails:

1. Command-Line Quick Fix with unrtf #

If you want a no-code, fast solution, the unrtf tool is perfect for yanking embedded objects straight out of RTF files. It’s open-source and works across most platforms:

• First, install it (Ubuntu/Debian: sudo apt install unrtf; macOS via Homebrew: brew install unrtf; Windows can grab pre-built binaries from its official repo).
• Run this command to extract attachments to a subfolder:

  unrtf --extract attachments your_rtf_email.rtf
  

This will dump all embedded attachments as their raw source files, no extra hoops needed.

2. Python Scripting for Custom Workflows #

If you need to integrate this into an automation pipeline or tweak the extraction logic, use Python with libraries built to parse RTF structure:

Option A: Pure Python with rtfparse #

rtfparse can dig into RTF elements and locate embedded OLE objects (the most common way attachments are stored in RTF emails):

1. Install the library:

   pip install rtfparse
   

2. Example code to extract and save attachments:

   from rtfparse import RTFParser
   
   parser = RTFParser()
   with open("your_email.rtf", "rb") as f:
       doc = parser.parse(f)
   
   # Loop through all embedded objects in the RTF
   for idx, obj in enumerate(doc.embedded_objects):
       # Check if the object is an attachment (adjust based on your RTF's structure)
       if hasattr(obj, 'name') and obj.name:
           # Save the raw attachment content to a file
           filename = f"extracted_attachment_{idx}_{obj.name}"
           with open(filename, "wb") as out_f:
               out_f.write(obj.content)
           print(f"Saved attachment: {filename}")
   

Option B: Windows-Specific Outlook Integration #

If you’re dealing with Outlook-sent RTF emails, using pywin32 to tap into Outlook’s native API is foolproof—Outlook handles the RTF parsing internally, so you don’t have to mess with low-level structure:

1. Install pywin32:

   pip install pywin32
   

2. Example code to fetch attachments directly from Outlook:

   import win32com.client
   
   # Connect to Outlook
   outlook = win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI")
   inbox = outlook.GetDefaultFolder(6)  # 6 = Inbox folder
   messages = inbox.Items
   
   # Locate your target RTF email (adjust the filter to match your email)
   target_email = None
   for msg in messages:
       if msg.Subject == "Your RTF Email Subject" and msg.BodyFormat == 3:  # 3 = RTF format
           target_email = msg
           break
   
   if target_email:
       # Save all attachments as raw source files
       for att in target_email.Attachments:
           save_path = f"C:\\your\\save\\path\\{att.FileName}"
           att.SaveAsFile(save_path)
           print(f"Saved attachment to: {save_path}")
   

Key Tips to Avoid Pitfalls #

• OLE Object Nuances: Most RTF attachments are stored as OLE objects, so tools that understand OLE (like unrtf or Outlook’s API) will be way more reliable than basic text parsers.
• Encoding Checks: If your extracted content looks like a long string of random text, it might be base64-encoded. Try decoding it with Python’s base64 module before saving.
• Encrypted RTF: If the RTF is password-protected, you’ll need to decrypt it first using tools like LibreOffice or specialized RTF decryption utilities.

Hope these methods get you the attachment content you need—let me know if you hit any snags with specific RTF email formats!

内容的提问来源于stack exchange，提问作者m vamsi